DIY ESS - Charger Side New Design tested with 6 Chargers

Last night, after wiring the last Grid Tie Inverters AC cables, and triple checking the leads polarities, I finally tested the new Charger Side design with 6 Chargers in parallel using the Forced Charge Mode of my LiFePO4 DIY ESS

Everything went  fine

6 Chargers Stack

Control Board overview

LiFePO4 DIY ESS overview

Wattson Anywhere Power Usage during the charge: one hour from 22:45 to 23:45

Dual Relay Programmable Voltmeter: voltage goes up nicely

and we are charging at 556.5W (/6 = 92.75W per charger, so a little less than a 100W)

New negative battery pack charger lead

CALB CA180FI Battery Pack with its protective see through lid 

LifePO4 ESS - Control Board Rebuilding Update

As of last night, this is where I ended with my BESPSS control board rebuild:

Overview of the left side of the board, the right side being the relay activated outlets

- Heavy gauge wire connecting battery pack to Kilovac contactor cut and screwed

- USB connector for Wattson USB connector (providing colors voltages)

- Charger leads input terminals, with positive connected to charger automotive relay, going through the Ampmeter, and to contactor battery positive lead; I am using solid core 2.5mm² wires here to handle the 10A coming from the charger

- A automotive fuseholder and 3A fuse are mounted vertically to save space

- The main swith is screwed to the board (was already done last time I think)

- The Arduino board is not moving

- The programmable dual relay Voltmeter is fitted between the Arduino board and the main switch 

I also ordered a 24V automotive lighter socket USB converter, that will provide 5V to the micro USB used to power the Arduino board (I had problems with the power supply using 12V); After testing it, I will probably open it and only keep the PCB connecting the battery 24V to its input and will plug the USB to micro USB cable in its USB output

LiFePO4 ESS - Changes to the control board

Another rainy weekend here, so it was easier to find motivation to work on the re-building of my LiFePO4 ESS control board: 

The idea is to put all the parts on the main board and detach them from the battery pack, charger and grid tie inverters

First Idisconnected the programmable voltmeter wires

Ampmeter too was removed along with the automotive 24V relay and the Tyco Kilovac contactor

I tried several times to arrange parts on the board 

and finally came out with this layout

The next day, it was time to make a strong support for the main switch (3 postions: 0, Charger, Grid Tie Inverters)

A used a left over piece of aluminum angle, drilled a 12mm diameter hole in it  

and cut if just the width of the big 24V 15A switch

(almost) finished product 

I then drilled 4 holes at each corner of the flat part to mount it very securely to the board

Here it is installed

Note that I got rid of the 2,5mm solid core wires going to each grid tie inverter; I am now using a thick multithreaded cable to connect the battery pack to the contactor, and the contacter to the grid tie inverters stack

A better view from the top: The Kilovac contcator is mounted flat with 2 screws

I will now have to work on the charger relay, charger leads inlet, fuse and wires layout

My father was kind enough to repair one of my grid tie invrter which had a shorted MOSFET; since it is not the first time, he used a spare one from a previous repair and wrote its reference on the post-it: MOSFET SSF7508

Since I do not have a 30A automotive fuse I simply used a 25A one, which should be enough to prtect the DC side, and anyways the input current goes up to 10, 15A maybe, not more

I then added this 6th grid tie inverter to my stack and will try it out with the rest when everything is functional

Note that I also added the 24V 10A LiFePO4 charger on top o fthe stack and it fits perfectly there :-)

To be continued ....

Relays and Electronics arrived

Some more Relays and Electronics arrived yesterday, I can now start playing with all that and hopefully will be posting some more soon

I was never really interested in electronics before I really started to work on this project, so I have to buy the starter's kit (bread bord, wires, resistors, capacitors, LEDs, potentiometer, switches, buttons, mini servo,) :-)

This is how I would set up my 6 5V / 220V relays to activate the Grid Tie Inverters

PS: For those of you who might wonder what this pieces of wood are: They come from Japanese Fishcakes, very usefull :-)

Welding cables onto Wattson PCB to read Color Codes

It was not trivial because of the tiny dots I had to weld the wires to and because of the risk of damaging the PCB / components on the other side by overheating the area, but I managed to do it : Welding tiny cables onto Wattson PCB to be able to read the voltage of each color LED

Before, heating up the soldering iron

I easily put some solder on the 3 dots diagonaly placed on the board (left) and on tested soldering the ground wire (right)

Done, and I was releaved that Wattson still displays everything correctly after that step

It's easier with a good LED light to see the fine details

Now testing color mode: it works too

and I can read voltages :-) (blue & red LED here)

With green now (switched on sevral Grid Tie Inverters for that)

I had to drill a little hole in the back panel of Wattson to fit the cable

I am using a old USB mouse cable, that provides a standard plug with 5 contacts and I need 4 here (ground, blue, green, red), so I put a red label onto the USB cable next to the plug warning that this is not a normal USB plug and should NOT be plugged into a computer for example (that would be bad...)

Reading voltages of blue and red LEDs

The USB plug plugged into a USB outlet and voltmeters leads attached to screw terminals

Voltages are going up and down, because Wattson "glows", it is not a solid color, butI realized that colors are more or less intense dpending on the energy level of the usage and the generation, so I can read the corresponding voltages and deduct what is going on ...

Water heater is on, all red now (very intense = 4.53V here) and blue is 0V